Airplane



Oct. 16, 1923. 1,471,243

H. L? COFFIN AIRPLANE Filed Dec. 5, 1919 s Sheets-Sheet 1 V fnvenfor:

fi erfierilawfazi fifth Oct. 16, 1923. 1,471,243

H. L. COFFIN AIRPLANE Filed Dec. 1919 3 Sheets-Sheet 5 fnveniar:

By/u's viii? W Patented @et. 1%, 1923.

HERBERT LAWTDN COFFIN, OF NEW Y0 AIRPLANE.

application filed December 8, 1919. serial No. seaoar.

To all whom it may concern:

Be it known that I, HERBERT LAw'roN CorrIN, a citizen of the United States, residing in New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Airplanes, of which the following is a specification.

This invention relates to that class of machines for aerial navigation which are now usually designated as air-planes, and it is applicable to heavier-than-air machines, in general. The present improvements relate more especially to the construction and equipment of the wings for airplanes; and a principal object is to furnish an airplanewing ofv strong, simple and effective construction and comprising improved means for use in guiding and balancing the airplane while in flight.

One object is to provide improved means for securing an eflective lifting action and effect, and to do this without any interference,as by a tilting or other device pro'ectable above the upper (or top) surface of the wing,-with the force and regular flow of air over and near. to the upper surface, and thereby avoid the production above the wing of obstructive air currents which would.

tend to counteract the wing-lifting effect.

' A further feature and object is to furnish such an airplane wing in which the usual ailerons are not required, and which shall be provided with an elevating or balancing means organized and positioned for so acting upon the wings as to lift the same by the parts of such surface as regards the gli tof the wings through the air.

action of air currents, and which when not in use for such purpose are mid-zone portions of the upper and lower surfaces of the wing and thus operate normally as inte ral mg Further objects and advantages are pointed out and explained in the course of the following description' In the accompanying drawings forming a part of this specification, Figure 1 is a perspective view drawn on a small scale, for

showing the arrangement of an airplane having the upper wings thereof made in accordance with the present invention.

Fig. 2 is a plan view on an enlarged scale,

of one said wing; and, Fig. 3 is across-sectional view of this wing, drawn on a scale corresponding to t a of ig-'2.

Fig. 4 is a partial section on a much larger scale, for showing the mid-zone portion of the win including the panel-system, and is illustrative of the mode of operation of the invention.

Fig. 5 is a view similar to Fig. 3, andis drawn to illustrate, in a diagrammatic manner certain features of the mode of'action, as hereinafter more fully explained.

Figs. 6 and 7 show one modification of the mechanism of the wing, and illustrate the mode of action thereof.

Figs. 8, 9 and 10, are series of diagrams explanatory of certain features and functional relations involved in the operation of the wing mechanism.

Fig. 11 is aview illustrative of a modified panel-actuating means.

Similarcharacters designate like parts in all the views.

The present improvements, are herein shown applied to that class of airplane wings in which a frame is enclosed between upper and lower coverings formin the external surfaces of the wing. Said rame, in order to secure suflicient rigidity, is usually, in present practice, built up of longitudinal bars, or beams, as B B combined with several crossbars,usually as indicated by dotted lines at H H (Fig. 2), and with a border member, as J, extending (preferably continuously) along the sides and around the outer end, E, of the wing. Also, these several frame members, besides being strongly connected by usual fastenings (not shown), are held in place and strengthened by diagonal tires or braces, which may be arranged in the 'well-known manner indi cated by the dash-lines G, G in Fig. 2.

In the mid-zone part of the .wing,-th1s bein also the deepest portion thereof,-a pane -chamber, C, is formed, for receiving a panel-system which comprises an upper and a lower panel and operating means' therefor. One said panel, as P, when in closed position, is in line with and forms a part of the upper wing-surface; and another said panel, P ,is in line with and forms a partof-the lower Wing-surface. Said upper panel, P is shown of a relatively narrow width, and the lower panel, P is much wider, so that the rearward edge, as 27*, of the lower one extends to a considerable distance rearwardly of the upper one,see Figs. 3, 4=,-and, to provide for this arrangement of the panels, said chamber C is made widest on the underside thereof, and has a rearward wall, 24, which is inclined downwardly and rearwardly, preferably on a low angle as illustrated, and through a distance, D, greater than the depth of the wing.

When the upper'surface panel, P is in closed position, (Fig 3), the upper wingsurface becomes continuous and thus provides for a free and unobstructed flow of air over and contiguous to the entire width of the wing; but,'-when said panel P is lowered as in Fig. 4, said air current on passing the point 23, expands downwardly into the space at S below the line L, thereby decreasing the air-pressure upon the panel, P and thus the capacity of the upper wing surface to resist upward movement is materially reduced. Also by reason of the direction of the aircurrents and the positions and peculiar arrangement of the current-guiding surfaces, (these including the, incline 24) an area represented in width by the distance 25, is prac- 'tically subtracted from the 'full area of said upper wing-surface, thereby further reducing said resistance thereof to upward movement when in flight. Thus said devices and construction may be said to constitute means for reducing the upward-movement-resisting surface of the wing concurrently with the actuation of said lower panel, P in a direction to increase the lifting effect thereof.

A further feature of practical importance (more clearly observed in Fig. 4) consists in the attacliment,or connecting of the lower panel P to the upper panel P so that in swin ing these panels downward, the rearwar edge 27 of said lower panel, follows in a curved line, 28, which is concentric with the joint or axis 23 of said upper panel; as a result, the opening, 26, is materially increased, as compared with the width such opening would have if said lower anel should be hinged at the point 29; tlius a relatively large outlet space is provided for the air current which flows downwardly against the inclined wall or lifting surface 24. To provide for this mode of action, the forward edge 27 of said lower panel is preferably arranged to swing above the rearward edge 29 of the forward portion 29 of the lower wing-surface; this arrangement also operates to narrow the acting area of the surface of said panel P -in proportion as this is swung downwardly from its closed position in Fig. 3 to its open position in Fig. 4.

The panel structure may comprise a light framework (herein only partially shown) suitable in arrangement and strength for carrying the panel-sheets, as P P and the inclined rearward wall-surface P each .of these three sheets, or surfaces, may be made of such kinds of material,these including metal, wood or fabric,as usually used or adapted to be employed, for the lower and upper coverings or surfaces of the wing itself. This panel-frame is herein indicated as being hinged at 23 to a member or bar, ofthe wing-frame in some convenient manner. In practice, said panel-surfaces P P "and said wall-surface P may be made of a single piece of such a fabric or material, this being folded over said frame-work and fastened thereto; the panel-system when thus organized and covered, is operable upon said axis, .23, as a single member of the wing, and when fully closed (Fig. 3), the wall surface 1 thereof lies near to the inclined wall 24 of the wingf The connected panels, P P may be conveniently dperated by means of a. controlapparatus substantially such as commonly.

used on air-planes for similar purposes, (not herein shown), a suitable connection being made by a wire, to, attached to the lower panel P whereby to pull this panel down from its zero position in Fig. 3, into a working position, Fig. 4. For closing the panels, when the wire w is relaxed, a spring, as R, of suitable power may be connected to the lower panel at R, and arranged (preferably,as herein -shown,with1n the interior space of the wing), to react against an abutment, as 29 but other panel opening and closing means may be employed, if desired, instead of those here described. WVhen the panels are fully closed while the airplane is in flight, they normally tend to remain closed independently of said spring, R, owing to the larger area of, and greater air-pressure under, said lower panel P as compared with said upper panel P Said complete panel systems, as will now be evident, each comprises three surfaces, as P P P each having a different position and function, not only in the panel-system itself, but also as to the coactive relations thereof to the adjacent parts of the main surfaces of the wing. Each panel system when closed constitutes, in effect, a part of the upper and lower wing surfaces, and is inoperative otherwise than as a part of the wing; but when lowered,see Fig. 4, and the description thereof,each panel-system is operative for raising (but not for lowering) the wing during flight. In order, therefore, to balance or otherwise properly control the airplane in flight, only one of the two panel systems,- -as P or P Fig. 1,should be depressed at one time; this mode of operation vmay be readily accomplished by suitably arranging the connecting wires, as w, to the usual centrally located control lever,'not herein shown. When the two panel-systems, one in each of a pair of oppositely-disposed wings, are depressed at the same time, it is evident that the normal effect will be to make the airplane climb more rapidly.

The diversion of air from the upper surface of the wing, before this air reaches the mamas rearward part of that surface, tends to reduce the air pressure in that rearward zone, and thereby assists the uplifting of the wing by the increased pressure below the wing. The air so diverted is directed into the normal low-pressure area, or zone, that is directly in the rear of the pressure-panel P when this panel is depressed, and thus supplies air to counteract the otherwise normal tendency to the forming of a condition naturally operating against said pressure-panel or mid-zone, panel of the wing. Thus I securea single stream of air down through the I able positioning of the area, or center, of the I tions on either side of wing-lifting effect is naturally obtained; also, by the relative widening of outlet 26, as described, a relatively larger flow of air against the incline 24, is secured, and a more complete filling to, or nearly to, normal pressure, of the low-pressure zone normally formed at 31 (Fig. 4) rearward of the panel P when this is depressed during flight, into its wing-lifting position.

Said wing-lifting efiects, by the means and action described, are brought into locaa vertical line, V, which represents the usual line of balance of the airplane; in flight, of course, this line Will move forwardly and backwardly, will fluctuate, to some extent under the rapidly changing conditions. Forward of such position line V, (see Fig. 5), there is a plusnormal pressure, at 32 underneath a normal pressure, at 33, thus producing on the forward part of the wing, a lifting effect indicated by arrow 34, Fig. 5. And, rearward of said line V, there is produced at 35 a compensated pressure which is about equal to normal pressure, and is located directly below'an area of minus-normal pressure at 36, thus producing on the rearward part of the wing, a lifting efl'ect indicated by the arrow 3 Thus the two lifting effects,-- represented, respectively, by arrows 34, 37,-are.coactive, one forward and the other rearward of line V, in a manner for conserving the proper balance of the airplane.

As further illustrated in Figs. 8, 9, the conduit wall P of the panel-system may be 4 considered as being pivoted to the wing at 23, and thus bodily shiftable from a closed position and by a swinging movement to successive open positions, as 38, 39, 40, Fig. 8. In position, 38, the wall l? lies close to the fixed inclined wall 24 of the wing, and when swung downwardly,thereby moving both ends in the same direction at the same time,the lower end 27 moves more rapidly than the upper end 41, thus producing a conduit channel or flue, S, (Fig. 9), bounded by the two plain and diverging wall surfaces, P 24, and having at the lower end a width, as 26, materially greater than the width, as 25, at the upper end, so that the I degree of taper of the conduit or channel increases, or is progressively amplified in proportion to the extent to which the width thereof is increased. This form and mode of action of the channel S is deemed to be particularly favorable for efi'ectively directing the transfer of air from the normalpressure area, at 33, above the wing to the low-pressure area otherwise normally formed at 35, and already described, for thereby, through a compensating action, overcoming the effect normally due to the loss of air in said area 35. Inthe channel S, the fiow of air seems to correspond in principle with the flow in the discharge end of the wellknown Venturi tubes. The stream of air in said channel S, it should be noted, is drawn from a point forward of said balance-line V, and is discharged into a space rearward of the lower panel-zone.

In a preferred construction thereof, as v herein shown, see Fig. 10), the line of the channel-wall 24, if continued as at 24,

passes the wall-pivot 23 by a distance 240, substantially, or very nearly equal to the depth of the wing, so that said distances may be said to correspond; similarly, the width of the wall 24 (from point 43 to point 44) is in correspondence with the prolongation 24*, from point 44 to the point 45, where the distance by line 24 (from the pivot 23) is at right-angles to such prolongation 24. From this comparison it will be seen how the pivot point 23 is here shown on a line, 46, midway of the angle subtended by the line of the channel-wall 24 and the line of the lower panel P thus producing a specific arrangement which has symmetrical features-and is well proportioned for eflective action.

By means of the present improvements, the lifting efi'ect required for balancing is produced, of course, by an increase of airpissure on the underside of the wing, but I accomplish this while avoiding an increase of air-pressure over any portion of the upper "surface of the wing. The air currents passing above the wing, as at arrow 47, (Fig. 5), glide along smoothly and tend to spread downwardly,owing to the inclination of the wing as a whole, (see Fig. 3), i

to its line of forward movement,--thereby normally reducing the air-pressure upon said upper wing-surface, and this effect is further increased by the diversion downwardly through the guide-channel S of a ortion of such over-wing air currents. his diversion, it should be noted, is accomplished without interposing any obstructive'means or device into the normal path of said over-wing upper currents, and

producing higher air pressures in some areas above the wings and so counteracting in large measure the lifting effect of any increase of air pressure below the wings. Especially, I' avoid the diversion by any current-intercepting or projective vane or edge, of any stream of air from above the wing and into a zone of increased air pressure below the wing; and, contrary to that common practice,in which two such zonepressures operate in a conflicting manner,- I only cause one air-current to flow downwardly, and this current is guided directly into an under-wing zone of relatively lowpresure which serves as an active but'noninterfering means for drawing such current, as by a suction, away from and out of the main air-current, flowing over and contiguous to the wing. Also, I divert high pressure air from the top of the wing to the underside thereof, thereby increasing the pressure under the. wing (and rearward of said panel P), for lifting effect, Thus I secure, with a high efficiency and a minimum of friction and loss of power, a normal, harmonious and complete coaction of all the means and surfaces employed, and of all the air currents, including the single one thus especially produced and utilized.

Instead of arranging the two panels, P I, to be swung in unison as herein illustrated, they may be arranged in some instances to be operated concurrently but with different relative angular rate of movement; this further improvement, although broadly Within the purview of my present invention, is not specifically claimed herein, but is intended to constitute in part the subject matter of a separate application to be concurrently pending herewith.

In the construction of the wing shown in Figs. 3 and 4, the frame-work has the interior space thereof,excepting the panelsystem-chamber in a mid-width zone thereof,covered in by upper and lower facings, or surfacings, as N, N which are separated, and which properly may consist of either metal or fabric, or other suitable surfacing sheets or layers, and these may be applied and secured, and drawn, taut, in accordance with a. well-known practice.

In that longitudinal portion of the wing, (as the length-zone 48, between lines 49, 50, Fig 3), in which said chamber, C, is located, the continuity of said upper and lower surfacings is interrupted by said chamber or chamber-space, so that said upper surfacing comprises a forward zone, and surface or area N and a rearward zone and surface or area N similarly the lower surfacing comprises a forward zone and under-surface, N and a rearward zone, and undersurface N Thus there are in said lengthzone 48, forward and rearward wingzones corresponding to said forward and rearward surfaces, on both the upper and the lower surfaces of the wing; and, since the panels P P', at their forward edges 51, 52, operably join with the rearward edges of said forward zone-surfaces N and N respectively, of the wing, therefore said panels P and P when in their closed position, Fig. 3, constitute rearward continuations,which are also, in av sense, alined continuations,of said upper and lower forward wing-zones and surfacings, N and N respectively, and thus connect, across said mid-width zone, as by a substantially uninterrupted and alined surface the said forward and rearward zone-areas of the upper and lower wing-surfaces, respectively.

A modified construction or embodiment of the invention is illustrated in Figs. 6 and 7. In this instance, the forwardly-joined panels P P (of the panel system) are operated in thesame manner as in the principal views (Figs. 2 to 5), but the coacting downwardly and rearwardly inclined wall or surface, 24, is here shown arranged on a supplemental panel-system, I" which is operably connected at its rearward edge, 53 to the narrow rearward zone 54, of the wing. The main panel system, comprising the surfaces P. P of the under-lapping panel and P P of the over-lapping panel, and the guide wall or face 24 is or may be the same in the construction in Figs. 6 and 7 as it is in the arrangement of Figs. 2, 3, and 4: the position of the coacting guide-wall 24 in these latter iews is shown by the line in Fig. 6.

In said view, Fig. 6. said guide-wall 24 is not only movably supported. but is also reversely-operable in relation to panel system P; when the latter airplane member. I, is lowered the panel-member P is raised. so that these two airplane-members, P and I are swung, or partially rotated, about axes, as 53, 23, positioned on the reverse sides thereof, respectively, these two rotative movements-being, however, in the same direction, as indicated by the circular arrowlines 56 and 57, drawn around said axes. respectively. The members P and F may be operated in a convenient manner by any suitable rods, or connections as for instance, by rods 58 and 59 connected to arms on a rocker-shaft, 60, in the manner shown; this shaft may be supported on the lower wing (in the case of a bi-plane) or otherwise, andmay be actuated by a handle, as 61, or by other well-known shaft-position-controlling means, (not herein shown),

The additional improvements herein illustrated in Figs. 6 and 7 while deemed to be within the purview, broadly, of my present invention, are not specifically claimed herein, but will constitute in part the subjectmatter of a separate application to be concurrently pending herewith.

For the purpose of securing a high degree of efficiency in the practical operation of the system herein set forth, it is deemed to be advantageous to have the zones, or zone-portions comprised in the wing transversely thereof arranged and proportioned in a manner substantially as follows :The forward zone, Z (Fig. 3), has a fixed relation to the wing, and at its rearward edge has a depth in accordance with 'thevertical distance between the spaced-apart upper and lower surfaces of the wing. The mid-zone Z is hinged (that is, operably connected) at its forward edge to the rearward edge of said forward zone, the axis thereof being preferably (for reasons elsewhere herein stated) close or contiguous to said upperwing-surface. The rearward zone Z is shown in Fig. 3 as having a fixed relation to the wing; but in some instances, as in Fig.

. 7, (and particularly when applied to large airplanes) this wing-zone may be operablysupported, as already explained. Saidmidzone Z underlaps the rearward zone Z by aconsiderable distance, which is preferably about one-third, or between one-fourth and one-half, of the width ofthe mid-'zone, and, also, greater than the spaced-apart distance (as 57, Fig. 4) of said upper and lower wing surfaces, thereby securing a low angle, as for instance, an angle of less than degrees of the inclined walls or surfaces N and 24, as clearly indicated in the drawings.

Instead of connecting the two panels P and P (as described in connection with 4), for actuation of the upper panel P by or from the lower panel P each of these panels may be actuated independently of the other. This arrangement is illustrated in one form thereof in Fig. 11, where one ordinary rock-shaft, 63 has an arm 64, operably connected by a rod 65 tosaid lower panel; and, a second rock-shaft, 66, similarly has an arm 67 operably connected by rod 68 to the upper panel P Said rod 68 may pass through a small opening at 69 in the lower panel, when the use of this detail shall be found convenient. In practice, ofcourse, the shafts 63, 66 may be located in any convenient or suitable position on the frameworkof the airplane, and the panel-actuating connections65, 68 may 'be of such character and length as found necessary in any particular instance; also, said shafts 63, 66, maybe extended to such a length as required, and be manuall or otherwise operated by ordinary or suitable control means, (not herein shown).

When thus or similarly arranged, (Fig.

11) the lower and supportive panel may be lowered, as indicated at P while the upper and non-supportive anel P remains closed, as there shown by so id lines; also, the upper panel may be swung down, as indicated by dotted lines at P whether said lower panel be then iii a closed or a depressed position whether operated independently or concurrently with the lower anel. Thus the upper panel P and means i er operating the same, may be said to constitute a means whereby to admit air (from above the wing) to the opening, (at 28, Fig. 4) between the rearward side 27 of the lower panel and the forward side of the wing-zone Z which is rearward of the open mid-zone of the wing.

Having thus claim- 1. In combination, an airplane wing having near each outer end of the wing. an opening through the wing extending longitudinally of the wing in an inward direction, each opening having a downwardly and outwardly inclined side whereby the opening is of greater length at its bottom than at its top; and a movable panel for each of said openings for normally closing the same, the panel having adjacent to the inclined side of described my invention, I

the opening a downwardly and outwardly rection beneath the under surface of the wing for lifting the wing.

2. In combination, an airplane wing having near each outer end of thewing an opening through the wing extending longitudinally of the wing in an inward direction, each opening havinga downwardly and outwardly inclined side whereby the opening is of greater length at its bottom than at its top; and a movable panel for each of said openings for normally closing the same, the panel having adjacent to the inclined side of the opening a downwardly and outwardly inclined side whereby the panel is longer on its bottom edge than on its top edge and is conformably engageable in the opening, the upper and under surfaces of the panels when inclosing position mer 'ng with the upper and under surfaces oft e wing; said panels being movable for unclosing the openings for relieving air pressure on said wing when the airplane is in upward flight and causing passage of the air downwardly through said openings and in an outward direction beneath the under surface of the wing for lifting the wing.

3. In an airplane wing, in combination, a frame having upper and lower surfacings with a depth-wise distance between them and also having in amid-width zone thereof a chamber extending depth-wise as an opening entirely through the wing and dividing the wing into forward and rear zones; a panel having upper and lower surfacings with a depth-wise distance between them, and pivotally connected to the forward zone at the forward edge of its upper surfacings and the rear edge of the upper surfacing of the forward zone; the forward edge of the lower surfacing of the panel being adapted during pivotal movement to dispose itself above and adjacent the rear edge of the lower surfacing of the forward zone, thereby to provide, at all times, a merging of said lower. surfacings of the panel and forward zone with each other.

4. In an airplane wing, in combination, a frame having upper and lower surfacings with a depth-wise distance between them, and also having a mid-width opening extending depth-wise entirely through the wing and dividing the wing into forward and rear zones; and a panel having upper and lower surfacings with a depth-wise distance between them, and pivotally connected at the forward edge of its upper surfacings with the rear edge of the surfacing of the forward zone; the forward edge of the lower surfacing of the panel being adapted at times during pivotal movement to dispose itself just above and at other times substantially flush with the rear edge of the lower surfacing of the zone.

, 5. In an airplane wing, in combination, a

frame. having upper and lower surfacings with a depth-wise distance between them, and also having a mid-width opening extending depth-wise through the'wing and dividing the wing into forward and rear 7 zones; and a panel having upper and lower surfacings with a depth-wise distance-between them, and pivotally connected at the forward edge oflits upper surfacings with the rear edge of the surfacing of the forward zone.

6. In an airplane wing, in combination, a frame having upper and lower surfacings with a depth-wise distance between them, and also having a mid-width opening extending through the wing and dividing the wing into zones and provided with a downwardly inclined face; and a panel'pivotally connected to an edge of the opening and having its downwardly inclined edge opposite to the pivot edge provided with a surface adapted when the panel is open to provide a downwardly inclined passage.

7. In an airplane wing, in combination, a frame having upper and lower surfacings with a depth-wise distance between them, and also having in a mid-width zone thereof a chamber extending depth-wise as an opening entirely through the wing and dividing the wing into forward and rear zones and provided with a rearwardly and downwardly inclined rear face; and a panel being pivotally connected at its forward edge with the rear edge of the forward zone, and having its rear surface downwardly and rearwardly inclined and adapted when the panel is open to provide a rearwardly and downwardly inclined passage.

8. In an airplane wing, in combination, a frame having upper and lower surfacings with a depth-wise distance between them, and also having a mid-width opening ex tending depth-wise through the wing and dividing the wing into forward and rear zones and provided with a rearwardly and downwardly inclined rear face; and'a panel having upper and lower surfacings with a depth-wise distance between them, and pivotally connected at its forward edge with the rear edge of the forward zone, and having its rear surface downwardly and rearwardly inclined and adapted when the panel is open to provide a rearwardly and downwardly flaring passage.

9. In an airplane wing, in combination, a frame having upper and lower surfacings with a depthwise distance between them, and also having in a mid-width zone thereof a chamber extending depth-wise as an opening entirely through the wing and dividing the wing into forward and rear zones and provided with a rearwardly and downwardly inclined rear face; and a panel having upper and lower surfacings with a depth-wise distance between them, and pivotally connected at the forward edge of its upper surfacings with the rear edge of the surfacing of the forward zone, and having its rear upper surface downwardly and rearwardly'inclined and adapted when the panel is closed to engage fiat against said rear face of the opening and when the panel is open to provide rearwardly and downwardly dlvergingsurfaces forming a rearwardly and downwardly flaring passage.

10. An airplane wing having for a portion of its length and transversely thereof three zones, viz., a forward zone in fixed relation in and to the wing; a mid-zone hinged on an axis at its forward edge to the rearward edge of said forward zone; a rearward zone having the forward edge thereof overlapping the rearward edge. of said mid-zone by a distance of more than a closed position in which this mid-zone forms an alined continuation of and between the lower surfaces of the forward and rearward zones.

' 11. In an airplane wing, in combination,

a wing-frame with upper and lower surfaces and having longitudinally thereof a chamber-form wing-opening in a mid-width zone thereof, and having said wing-opening extending farther rearward on said lower surface than on said upper surface; an

upper panel operably joining said upper surface at the forward side of said wing-open ing, and a lowerpanel operably joining said lower surface at the forward side of said wing-opening, said upper panel being arranged to swing downwardly into said wingopening and .said lower panel to swing downwardly below said wing-opening to thereby increase the lifting efi'ect of said lower panel.

12. In an airplane wing, in combination, a wing-frame with upperand lower surfaces and having longitudinally thereof a chamber-form wing-opening in a mid-width zone thereof, and having said wing-opening extending farther rearward on said lower surface than on said upper surface; an

upper panel operably joining said upper surface at the forward side of said wingopening, and a lower panel operably joining said lower surface at the forward side of said wing-opening; and means connected and arranged for operating said panels to swing said upper panel downwardly into said wing-opening and simultaneously toswing said lower panel downwardly below said wing-openingto thereby increase the lifting effect of said lower panel and to also open a passage for a down-flowing current of air rearward of the two panels, substantially as and for the purpose set forth.

13. An airplane Wing comprising a framework enclosed between spaced-apart upper and lower wing-surfaces, and having for a portion of its length and transversely thereof three zones, viz., a forward zone in fixed relation in and to the wing; an operablysupported mid-zone hinged at its forward edge to the rearward edge of said forward zone; and a rearward zone in a fixed relation to the -wing and having the forward edge thereof overlapping the rearward edge of said mid-zone, and said mid-zone being of a width to underlap said rearward zone by a distance of between one-fourth and oneand lower wing-surfaces, and having for a portion of its length and transversely thereof three zones, viz., a forward zone in fixed relation to the wing; a mid-zone hinged at its forward edge to the rearward edge of said forward zone and hinged on an axis contiguous to said upper surface; and, a rearward zone in a fixed relation to the wing and having the forward edge thereof overlapping the rearward edge of said mid-zone, and said mid-zone being of a width to underlap said rearward zone by a distance of more than one-third the width of said mid-zone.

15. An airplane wing comprising a framework enclosed between spaced-apart upper and lower wing-surfaces, and having for a portion of its length and transversely thereof three zones, viz., a forward zone in fixed relation to the wing; a mid-zone hinged at its forward edge to the rearward edge of said forward zone and hinged on an axis contiguous to saidupper surface; and, a rearward zone having the forward edge thereof overlapping the rearward edge of said midzone, and said mid-zone being of a width to lower and forward wing-zone surfacing and thereby closing said wingopening; means for depressing said panel by lowering the rearward edge thereof without unjoining the forwardedge thereof; an upper mid-zone panel operably joining at its forward edge the rearward edge of the upper-zone surfacing of the wing Which is forward of said chamber and wing-opening; and, means conmeeting said upper and lower mid-zone panels for the concurrent operation of each one with the other.

17. An airplane wing comprising a framework enclosed between spaced-apart upper and lower wing-surfaces, and having for a portion of its length and transversely thereof three zones, viz., a forward zone in fixed relation to the wing, an open mid-zone, and a rearward zone in fixed relation and to the wing; a passage-way controlling pressureplane constituting when closed a mld-zone lower panel of the under wing-surface, said panel being closed against the passa e of air at its forward side, and operable ownwardly for the passage of air' at 1ts rearward side; an inclined lifting surface between the upper and lower wing-surfaces;

ing the wing, for thereby combining the lifting efl'ects of said inclined surface with said pressure-plane.

18. An airplane wing comprising a framework enclosed between spaced-apart upper and lower wing-surfaces, and having for a portion ofits length and transversely thereof three zones, viz., a forward zone in fixed relation to the wing, an open m dzone, and a rearward zone in fixed relation to the wing; a movable pressure-plane constituting when closed a mid-zone lower panel of the under wing-surface, said panel being closed against the passage of .air at its forward side, and operable downwardly for the passage of air at its rearward side; an inclined lifting surface between the upper and lower wing-surfaces. and on the rearward side of said open mid-zone. and having its forward edge above a medial line of said lower panel; and, means coactive with the pressure-plane for admitting air from above the wing and forward of said medial line to said inclined lifting-surfa e on the operating of the pressure-plane in a direction for raising the wing. for thereby combining the. lifting effects of said inclined surface with said pressure-plane.

19. In an airplane wing. in combination. a frame-work having upper and lower surfacings with an interior space between them. and also having in a mid-width zone thereof a chamber extending depth-wise entirely through the wing; a panel operably joining at its forward edge the rearward edge of the lower zone surfacing of the wing which 15 forward of said chamber and wing opening, said panel when closed formingan alined continuation ,of such lower and forward wing-zone surfacing and thereby closing said wing opening; means connected and operable for depressing the panel by lowering the rearward edge thereof without unjoining the forward edge thereof; and, means for reducing the effective upward-niovement-resisting area of the upper wing-surface concurrently with said depressing of the panel.

20. In an airplane wing, in combination, a frame-work having upper and lower surfacings with an interior space between them, and also having in a mid-width zone thereof a chamber extending depth-wise as an opening through the wing; a panel operably joining at its forward edge the rearward edge of the lower zone surfacing of the wing which is forward of said chamber and wing opening, said panel when closed forming a cohtinuation of such lower and forward wing-zone surfacing and thereby closing said wing opening; means for depressing the panel by lowering the rearward side thereof without unjoining the forward edge thereof; and, means for admit-- .tmg an air current through said win opening and directing this current un er the wing and to the rearward of said panel, on the depressing of the panel.

21. In an airplane wing, in combination, a frame-work having upper and lower surfac-ings with an interior space between them, and also having in a mid-width zone thereof achamber extending depth-wise as an opening through the wing; a panel operably joining atits forward edge the rearward edge of the lower zone surfacing of the wing which is forward of said chamber and wing opening, said panel when closed forming a continuation of such lower and forward wing-zone surfacing and thereby closing said wing opening; means for depressing the panel by lowering the rearward edge thereof without unjoining the forward edge thereof; and. means for admitting an air curnent through said wing opening and directing this current under the wing and to the rearward of said panel. on the depressing of this panel, such means com prising an upper panel operably joining-at its forward edge with the rearward edge of an upper and forward wing-zone surface.

HERBERT LAWTON COFFIN.

'Witnesses:

GEonoE J. BARTELS, FREDERICK T. Sass. 

